Data communication with use of DSRC (Dedicated Short Range Communication) has been conventionally utilized. DSRC is a wireless communication technique designed for vehicle communication specifically. DSRC is utilized by ITS (Intelligent Transport Systems), and it may be a broadcast service such as VICS (Vehicle Information and Communication Systems), or an individual communication service such as ETC (Electronic Toll Collection Systems).
For an individual communication service such as an ETC herein, since two-way data communication is performed between an on-road apparatus and a vehicle-side DSRC on-vehicle apparatus and a response is verified mutually, it is possible to keep the on-road apparatus wait when having a heavy on-vehicle processing load.
However, for a broadcast communication service such as VICS, since one-way data communication is transmitted from the on-road apparatus to the vehicle-side DSRC on-vehicle apparatus, there is a possibility that data cannot be processed when having a heavy on-vehicle processing load.
To solve the problem, a DSRC on-vehicle apparatus responding to the situation that exceeds processing capacities temporarily for processing data (i.e., “broadcast data”) of the broadcast communication service has been proposed in recent years (for example, see Patent Literature 1).
The communication device such as a DSRC on-vehicle apparatus receives broadcast data; however, the apparatus (hereinafter referred to as “processor”) for performing guide processing based on the received data is generally formed as a separate configuration. For example, broadcast data such as VICS is received at a DSRC on-vehicle apparatus from the road-side apparatus and transferred to a navigation apparatus, and then guide processing is performed in the navigation apparatus. Therefore, it is possible to purchase a DSRC on-vehicle apparatus later apart from a navigation apparatus. The communication device such as a DSRC on-vehicle apparatus and the processor such as a navigation apparatus are connected by a USB (Universal Serial Bus).
The Patent Literature 1 proposes how to receive broadcast data from a road-side apparatus in a DSRC on-vehicle apparatus.
However, when a DSRC on-vehicle apparatus transmits data to a navigation apparatus as described above, even when it is possible to receive data from a road-side apparatus in a DSRC on-vehicle apparatus as the processing load of a CPU in the navigation apparatus gets larger, there is a possibility that processing cannot be performed in the navigation apparatus. Thus, it is required to increase the processing capability of the CPU in the navigation apparatus. In addition, to realize a variety of functions other than the collaboration with the DSRC on-vehicle apparatus in the navigation apparatus, it is required to select a CPU by taking account of the realization of these functions. Accordingly, a processing load becomes a burden just before shipping of a navigation apparatus, and the reselecting of a CPU may happen as well.
It is noted that the burden is not necessarily restricted to data communication with use of DSRC, the similar burden may be generated when a communication device transmits the received data to a processor.